Electrochromic materials have been one of focuses in material science researches in recent years. Polymer electochromic materials have advantages of better coloring efficiency; fast electrochromic response; good chemical stability; easy preparation; longer cycle life; possession of color-memory function; and adjustable color shade, as compared to inorganic or organic small molecule electrochromic materials.
Rigidity of electroconductive polymer backbones usually imparts insoluble and infusible properties to polythiophene. Conventionally, polymer films are formed on the surface of an electrode via electrochemical polymerization. However, it is difficult to produce electrochromic devices on a large scale via electrochemical polymerization. Recently, the researchers have achieved sprayable operation of polythiophene electrochromic materials by incorporating various forms of side groups into the polythiophene derivatives with chemical modification methods to weaken interaction between polymer molecule chains such that polymers can be dissolved in organic solvents.
Among three primary colors, worldwide scientists have early researched and developed blue and red polythiophene electrochromic materials. However, the first type of green polythiophene electrochromic materials has not been synthesized by Wudl until 2004. Only a few of kinds of green polythiophene electrochromic materials have an ability to dissolve in organic solvents and form a film via spraying. Known green polythiophene electrochromic materials generally have poor transmittance difference and short cycle life.
It is rarely reported domestically as to the green polythiophene electrochromic materials, preparation and application thereof. In view of that, the present invention is provided.